Water Heater Leaking: What to Check First

If you find your water heater leaking, the first job is to stop more water arriving, and the second is to work out where it is coming from. A drip from a fitting on top or from the drain valve is often a repair. Water seeping from the tank itself usually means the tank is finished. Here is how to tell the difference safely, and when to hand it to a vetted, licensed local professional through One Call Home Pros.

The short answer

Most leaks around a water heater come from one of four places: the pipe connections on top, the temperature and pressure relief valve on the side, the drain valve near the bottom, or the tank itself.

The first three are parts that can be tightened, resealed or replaced. The tank is different. A steel tank is lined with glass and protected by a sacrificial anode rod. Once the lining fails and the steel rusts through, the tank cannot be patched, and the heater needs replacing.

Water under the heater is not always a leak, either. A gas heater can drip condensation when it first fires on cold water, and a nearby AC line or pipe can drip onto the floor beside it.

What to shut off first

Do these before anything else. They stop the leak getting worse and make the heater safe to look at.

1. Close the cold water supply valve on the pipe going into the top of the heater. Turn it clockwise until it stops.
2. For an electric heater, switch off its breaker at the panel. Heating elements burn out if they run with the tank draining.
3. For a gas heater, set the control knob to the off position as shown on the label. If you smell gas, leave the house and call the gas utility or 911 from outside instead.
4. Move stored boxes, rugs and anything else that can soak up water away from the heater.
5. Put a shallow tray or towels down, and take photos of where the water is collecting.

Where the water is coming from

Dry the area with a towel, then watch for a few minutes to see where fresh water appears.

• On top of the heater. Look at the cold inlet and hot outlet connections and the flexible supply lines. A loose or corroded fitting drips down the outside of the tank and can look like a tank leak.
• From the relief valve or its pipe. The temperature and pressure relief valve opens when the water gets too hot or the pressure too high. Water from its discharge pipe means the valve is doing its job or is failing. Either way it needs a pro. Never cap or plug that pipe.
• From the drain valve near the bottom. A drain valve that drips from its spout or around its stem can often be replaced.
• From under the tank, with no visible source. If the water seems to come from the base itself, or the jacket is rusty and wet, the inner tank has likely failed.

When to stop and call a pro

Water heater leaking from the tank is not a repair job, and it is not a homeowner job. Call a pro if:

• The leak is coming from the tank body or the base
• The relief valve is discharging or dripping
• There is rust on the tank, the fittings or the floor under it
• The water is hot enough to scald, or the tank is making popping sounds

Beyond the knob on the label, leave the gas line, the burner, the access panels and the venting alone. Do not try to drain a tank full of hot water yourself. Draining it is part of the replacement, and the pro does it with the water cooled and the heater isolated.

Which leaks mean the tank is finished

A leak from a fitting, the drain valve or the relief valve usually means a part. A water heater leaking from the tank body means the inside of the tank has corroded through. That happens from the inside out, which is why a tank can look fine on the outside until the day it does not.

Signs that point at the tank:

• Rust-coloured water from the hot taps only
• A wet patch that comes back under the heater after it is dried
• Rust streaks running down the outer jacket
• A rumbling, popping tank that has not been flushed in a long time

Florida specifics worth knowing

Many South Florida water heaters sit in garages, in utility closets beside the kitchen, or in a closet on an upper floor of a townhouse. A heater in the garage tends to leak onto concrete, which is easy to spot. A heater in an interior closet can leak into the floor, the baseboards and the next room before anyone sees it.

That is why a drain pan with a drain line matters for an indoor heater, and why the area’s hard water deserves attention too. Mineral sediment builds up at the bottom of the tank and speeds up the wear that ends in a leak.

How One Call fits in

One Call Home Pros does not hold a plumbing licence and does not do the work. When you call about a water heater leaking, tell us what kind of heater you have, where it is and where the water seems to come from. We then send a vetted professional who is licensed and insured for water heater work. The pro confirms the source, explains whether it is a repair or a replacement, and does the job. One Call vets the pro, arranges the visit and stays with you until it is finished.

You pay One Call, and One Call pays the pro. Ask what is included before work begins. If a new heater is the answer, financing is available; ask about it when you call. See water heater repair and replacement for more, or the pages for Coconut Creek, Sunrise and Hollywood.

Get the leak looked at

Shut off the water and the power first. Then tell One Call where the heater is and where the water is coming from, and we connect you with a vetted, licensed local pro.